“To All Whom It May Concern” is a triptych of documents from the Civil War that includes: 1. An erasure of the first page of a four-page letter written by Lyman Jones to his parents while he was held a prisoner of war in 1863; 2. A later photo of him with wife and two children; 3. His discharge orders, over which a second erasure is pasted—words cut from Walt Whitman’s “Song of Myself” as published in his 1860 edition of Leaves of Grass.